Tobacco is the leading cause of avoidable death worldwide, and its consumption is one of the major problems for public health, with repercussions for the whole population, smokers and non-smokers alike. Every year around 5 million people in the world die from tobacco related illnesses. If this trend continues The World Health Organization (WHO) estimates that by 2020 the number will have risen to 10 million.

Tobacco smoke is a major pollutant not only because of its carcinogenic effect but also as a significant risk factor in cardiovascular and respiratory diseases.

In relation to children the WHO estimates that 700 million, that is to say, almost half the children in the world, breathe in air that has been polluted by tobacco smoke and a large part are subjected to this atmosphere in their home because of their parents. According to the same source a child of a mother who smokes has a 70 % increased probability of suffering from a respiratory disorder.1

Most exposure to passive smoking happens during gestation and early infancy, a period when the effects are most damaging to the respiratory system.2

Children exposed to smoking in the home have an increased risk of sudden death syndrome, middle ear disease, including acute otitis; onset of asthma or exacerbation of symptoms where it already exists; an increase in Bronchial Hyperreactivity; increase in chronic respiratory symptoms; in acute respiratory disease with bronchitis, pneumonia and bronchiolitis requiring hospitalization,2–4 which is consistent with the results of the study of Carolina Constant and co. which found that the children of mothers who smoked are 2.1 times more likely to suffer from cough compared with children of non-smoking mothers (OR adjusted = 2.15; 95 %CI, 1.15-4.03; p = 0.017).5

Various studies have shown that exposure to tobacco smoke during gestation can inhibit fetal growth, lead to low birth-weight, more frequent spontaneous abortions, delayed lung development, lowered respiratory function, premature births.6

This epidemic needs a multidisciplinary response, centered on prevention, with an anti-smoking campaign and the prevention of exposure to environment of tobacco smoke.

To abide by the WHO Framework Convention for the control of tobacco the Portuguese Government passed the Decree-Law number 25-A/2005, November 8, pledging to strengthen their policies and measures to protect present and future generations from the devastating effects of tobacco, not only in terms of health but also in social, environmental and economic terms. Law number 37/2007, August 14, which came in to force in January 2008, put this convention into practice.

Legal restrictions on smoking in public places and anti-smoking campaigns are undoubtedly the most effective ways of promoting a healthy life-style.

The most efficacious means of protecting children from exposure to passive smoking in the home is to encourage parents to give up smoking or at least to warn them of the dangers of smoking in the house.

Family smoking habits may influence behavior in relation to taking up smoking and the children of parents who smoke run a much greater risk of becoming future smokers themselves.7,8

Smoking among adolescents has remained high and has become more widespread since the beginning of 1990s, principally among young adolescents.9

Most smokers started during adolescence, three of every five who experimented then became regular smokers. Even adolescents who adopt a high moral tone against the evils of smoking may well become smokers as they grow older. There are social pressures, in particular from their peers, associated with curiosity, emancipation, the desire to conform to the group, which lead to a desire to experiment.10,11 This is borne out in the study by Silvia Fraga and colleagues12 who find most significant the longing for emancipation, that is, to be adult (47 %), “the young begin to smoke because they think that they are already grown up”. Acceptance by one's peers is another important factor (44 %) in the formation of smoking patterns they found that “the young begin smoking because they are urged on by their peers” and feel under pressure.

The majority of young people are not aware that tobacco is so addictive and that when they want to give up they will have great difficulty is doing so without help.

Health professionals are responsible for promoting healthy life-styles by using a range of strategies centered on preventing young people from taking up smoking. In addition all forms of advertising must be banned. Of the various measures in place, the increase in the price of tobacco seems to be the most effective in reducing smoking among the young.

Health professionals have an important role in primary prevention, but, according to the WHO Framework Convention, so do teachers and parents who must become involved in the roll out of compulsory educational programs on the subject of tobacco, each program to be appropriate to the age and culture of the target group.